Long-term Safety and Dosing of OnabotulinumtoxinA: A Prospective, Observational Study.

[BACKGROUND] Although therapeutic treatments are intended to help alleviate symptoms associated with disease, safety must be carefully considered and monitored to confirm continued positive benefit/risk balance. The objective of MOBILITY was to study the long-term safety of onabotulinumtoxinA for treatment of various therapeutic indications.

[METHODS] A prospective, multicenter, observational, Phase IV Canadian study in patients treated with onabotulinumtoxinA for a therapeutic indication. Dosing was determined by the participating physician. Adverse events (AEs) were recorded throughout the study.

[RESULTS] Patients (n = 1372) with adult focal spasticity, blepharospasm, cerebral palsy, cervical dystonia, hemifacial spasm, hyperhidrosis, or "other" diagnoses were enrolled into the safety cohort. Eighty-three patients (6%) reported 209 AEs; 44 AEs in 24 patients (2%) were considered treatment-related AEs. Seventy-two serious AEs were reported by 38 patients (3%); 10 serious AEs in 5 patients (0.4%) were considered treatment related. Most commonly reported treatment-related AEs were muscular weakness (n = 7/44) and dysphagia (n = 6/44).

[CONCLUSIONS] In patients with follow-up for up to six treatments with onabotulinumtoxinA, treatment-related AEs were reported in <2% of the safety population over the course of nearly 5 years. Our findings from MOBILITY provide further evidence that onabotulinumtoxinA treatment is safe for long-term use across a variety of therapeutic indications.